A Randomized Controlled Trial on the Effect of Needle Gauge on the Pain and Anxiety Experienced during Radial Arterial Puncture

Australian and New Zealand Society of Respiratory Science position statement for arterial blood gas sampling

The assessment of gas exchange under varying ambient and metabolic conditions is an important and fundamental investigation of respiratory function. The gold standard is an arterial blood gas (ABG) sample; however, the procedure is not universally performed by medical scientists, is not standardised, and is typically taught by a subjective Halsted 'see one, do one' approach. The Australian and New Zealand Society of Respiratory Science recognised the need to create an ABG position statement that includes the required pre-requisite education, an evidence-based procedure and the minimum reporting and competency assessment requirements. This position statement aims to minimise patient discomfort, to improve puncture success rate and reduce the potential for sample handling and analysis error. Importantly, this position statement translates to all relevant health professionals, including medical officers, scientists, nursing staff and allied health.

Efficacy of Local Anesthesia for Radial Artery Puncture Pain: A Systematic Review and Network Meta-Analysis

We performed a systematic review and network meta-analysis (NMA) to assist clinicians in determining the optimal patient-specific method of analgesia during radial artery puncture by comparing radial artery puncture procedural pain. We included randomized controlled trials that assessed the prophylactic efficacy of local anesthesia for radial artery puncture-associated pain. We searched the Medical Literature Analysis and Retrieval System Online in January 2023, the Cochrane Central Register of Controlled Trials in January 2023, the Excerpta Medica Database in December 2022, the World Health Organization International Clinical Trials Platform Search Portal in January 2023, and ClinicalTrials.gov in January 2023. We synthesized the pain scores (0-100 scale) using the frequentist random-effects NMA model. We evaluated the confidence in each outcome using the CINeMA tool (https://cinema.ispm.unibe.ch/). We conducted an NMA of 1,619 patients across 14 studies on pain scores during radial artery puncture-related procedures for 12 interventions. Compared with placebo, mepivacaine infiltration and lidocaine spray probably reduce pain (mean difference (MD): -47.67, 95% confidence interval (CI): -61.45 to -33.89, confidence rating (CR): moderate; MD: -27.38, 95% CI: -37.53 to -17.22, CR: moderate). Of the 32 studies included, none reported systemic adverse events, such as anaphylaxis or local anesthetic systemic toxicity, or severe local adverse events. In conclusion, mepivacaine infiltration and lidocaine spray probably reduce the pain associated with radial artery puncture more than other local anesthesia.

Use of finer needles for venipuncture increases in vitro haemolysis despite reducing persistent pain and nerve injury: A retrospective study

BACKGROUND

Although venipuncture is minimally invasive, and is the most frequently performed medical procedure, it carries the small risk of causing persistent pain, including nerve damage. Recently, our hospital stopped using 22-gauge needles for venipuncture in outpatients and switched to using only 23- and 25-gauge needles. We investigated the impact of using only the finer needles on the incidence of persistent or neuropathic pain and the prevalence of haemolysis, as well as the impact of haemolysis associated with the needle change on other laboratory data.

METHODS

We retrospectively collected and analysed data on venipuncture-associated pain complaints made during the 1-year period prior and 1-year period after the change in needles, as well as the frequency of haemolysis before and after the change. We also focused on 90 cases that showed significant haemolysis after the needle change and compared the serum aspartate aminotransferase, lactate dehydrogenase, and potassium levels before and after the needle change.

RESULTS

The incidence of persistent pain was significantly reduced from 1 in 10,825 venipunctures before the change to 1 in 29,747 venipunctures after the change. Notably, no patients experienced neuropathic pain after the change. However, the prevalence of haemolysis was significantly increased. Additionally, the serum aspartate aminotransferase, lactate dehydrogenase, and potassium levels were significantly elevated in the cases that showed moderate to gross haemolysis after the needle change.

CONCLUSION

Using finer needles involves both advantages and disadvantages, and careful consideration is needed to determine which type of needle is in the best interests of the patient.

Spiced RCT: Success and Pain Associated with Intravenous Cannulation in the Emergency Department Randomized Controlled Trial

BACKGROUND

Peripheral venous cannulation is one of the most common procedures in medicine. A larger cannula allows higher rates of fluid to be provided if needed in a deteriorating patient; however, it is also perceived that larger-gauge cannula placement is associated with increased pain and procedural difficulty.

OBJECTIVE

This study aimed to compare the pain and procedural difficulty experienced during insertion between 18-gauge (18G) and 20-gauge (20G) cannulas.

METHODS

We conducted a single-blinded, randomized controlled trial on adult patients who required peripheral IV cannulation within a tertiary hospital emergency department between April and October 2018. Patients were randomized to either the 18G or 20G cannula group. The primary outcomes of the study-pain experienced by patients and procedural difficulties experienced by clinical staff-were recorded on two separate 10-cm visual analog scales. Other outcomes include first-attempt success rate, operator designation, complications, and the intent and actual use of the IV cannula were documented on preformatted questionnaires.

RESULTS

Data from 178 patients were included in the analysis. Eighty-nine patients were allocated to each cannula group. There were no statistically or clinically significant differences between mean pain score (0.23; 95% CI 0.56-1.02; p = 0.5662) and mean procedural difficulty score (0.12; 95% CI 0.66-0.93; p = 0.7396). between the two groups. There was no difference in first-attempt success rate (73 of 89 vs. 75 of 89; p = 0.1288), complications (2 of 89 vs. 1 of 89) between the 20G group and 18G group, respectively.

CONCLUSIONS

There was no significant difference between the 18G or 20G cannula for either pain experienced by patients or procedural difficulty experienced by clinicians.

Development and validation of a nomogram for predicting difficult radial artery cannulation in adult surgical patients

Background

Radial artery cannulation is an invasive procedure commonly performed in patients in the perioperative time, in the intensive care unit, and in other critical care settings. The current study aimed to explore the preoperative risk factors associated with difficult radial artery cannulation and develop a nomogram model for adult patients undergoing major surgery. This nomogram may optimize preoperative clinical decision-making, thereby reducing the number of puncture attempts and preventing associated complications.

Methods

This was a single-center prospective cohort study. Between December 2021 and May 2022, 530 adult surgical patients were enrolled. The patients were randomized into the training and validation cohorts at a ratio of 8:2. Radial artery cannulation was performed before the induction of anesthesia. Univariate and multivariate logistic regression analyses were performed to identify variables that were significantly associated with difficult radial artery cannulation. These variables were then incorporated into the nomogram. The discrimination and calibration abilities of the nomogram were assessed.

Results

One hundred and seventy-three (41.7 %) patients in the training cohort had difficult radial artery cannulation. Based on multivariate analysis, the independent risk factors were wrist circumference, anatomical abnormalities, BMI <18.5 kg/m2, grade II hypertension, hypotension, and history of chemotherapy and stroke. The concordance indices were 0.765 (95 % confidence interval [CI]: 0.719-0.812) and 0.808 (95 % CI: 0.725-0.890) in the training and validation cohorts, respectively. The calibration curve showed good agreement between the actual and predicted risks.

Conclusions

A preoperative predictive model for difficult radial artery cannulation in adult patients undergoing surgery was developed and validated. This model can provide reliable data for optimizing preoperative clinical decision-making.

Comparison of a Novel Thin-Walled 25-gauge Needle Push Button Blood Collection Set to a Standard 23-gauge Needle in a Cancer Patient Population

BACKGROUND

Phlebotomy can be an uncomfortable and even painful experience that increases in likelihood in patients who require frequent blood draws, such as those with cancer. The 25-gauge BD Vacutainer® UltraTouch™ Push Button Blood Collection Set has a smaller outer bore needle size and unique bevel configuration, which in theory should reduce pain associated with phlebotomy. Smaller needles typically cause less pain, however, they have a higher incidence of compromising the specimen integrity. Innovative engineering allows this particular needle to maintain a larger inner bore size similar to a standard 23-gauge needle. This study compares pain and specimen integrity between this novel device and a standard 23-gauge needle.

METHODS

Two cohorts of 190 patients each had phlebotomy performed with either needle. Pain experienced was assessed by patient surveys, rating pain from 0 (low) to 10 (high). Sample integrity was assessed by determining the hemolysis index (Abbott Architect c8000).

RESULTS

No statistically significant difference in median pain scores was observed between the 2 cohorts, P-value: 0.068. The 23-gauge cohort more frequently reported 3+ pain than the 25-gauge cohort, 14/190 vs 5/190. Pain scoring 1 and 2 was more frequent in the 25-gauge cohort, 84/190 vs 54/190. Pain scores of 0 were more frequent in the 23-gauge cohort, 122/190 vs 101/190. This stratification is statistically significant, P-value: 0.003. The 25-gauge needle showed no increase in hemolysis rates, P-value: 0.5.

CONCLUSIONS

Sample integrity was identical between both needles. The 25-gauge needle resulted in less 3+ pain, while pain scoring 1 and 2 was more frequent in the 25-gauge cohort.

Impact of Lavender on Pain and Anxiety Levels Associated With Spine Procedures

Background: To reduce pain and anxiety associated with interventional pain procedures, sedation is often used, with benzodiazepines, opioids, and propofol the most commonly used classes of drugs for sedation. However, patient coherence and ability to communicate procedural pain and abnormal sensations help prevent adverse outcomes. Therefore, discovering alternative therapies to mitigate the anxiety and pain associated with these procedures and to minimize risk is important. The aim of our study was to investigate whether lavender has an effect on pain and anxiety associated with lumbar epidural steroid injections and lumbar medial branch blocks.

Methods: In this randomized controlled study, 54 subjects were randomly assigned to 1 of 3 intervention groups, and 46 patients were included in the final analysis: experimental lavender group (n=17), control almond oil group (n=15), and placebo sterile water group (n=14). Patients wore a mask infused with either lavender, almond oil, or water for 5 minutes prior to and during their procedure. Patients rated their anxiety using the State-Trait Anxiety Inventory prior to and after the procedure based on how they felt during the procedure. Patients rated their pain according to the numerical rating scale. Outcome measures were a comparison of pain among the 3 groups and a comparison of the change in anxiety before and after the procedure among the 3 groups.

Results: The lavender group demonstrated the highest mean change in anxiety scores (9.9) compared to almond oil (5.3) and water (3.6) preprocedurally vs postprocedurally. The lavender group also reported the lowest mean pain level (3.8) compared to almond oil (5.6) and water (5.6). However, none of the differences between groups showed statistical significance at the P<0.05 level.

Conclusion: Lavender may have a clinically beneficial effect on anxiety levels and pain reduction.

To Explore the Haemostatic Effect of Compression Haemostasis Using an Ultrasonic Probe under the Guidance of Ultrasound after Radial Artery Puncture

OBJECTIVE

To evaluate a new haemostasis method using an ultrasound probe to compress the radial artery and haemostasis under direct vision to replace traditional manual compression of the radial artery.

METHODS

According to a random number table, 240 patients with gastrointestinal tumours who had undergone arterial puncture were divided into Group A (120 cases) and Group B (120 cases). In Group A, patients were under the guidance of ultrasound to confirm the vascular port, determine the compression position of the ultrasound probe, observe the degree of vascular deformation, and press the radial artery puncture port with pressure to stop bleeding under direct vision. In Group B, traditional manual compression was used. All patients received 5 min of compression for haemostasis, and haemostasis conditions were recorded after compression and 24 hours postoperatively.

RESULTS

The incidence of bleeding, haematoma, and skin ecchymosis at the puncture site after 5 minutes of compression in Group A was lower than that in Group B (P < 0.05). No significant difference was found between the two groups at 24 hours after the operation (P > 0.05).

CONCLUSION

The method using an ultrasound probe to guide radial artery compression to haemostasis is better than traditional manual compression when applied for compression haemostasis after removing the radial artery catheter.

Interventions to reduce arterial puncture-related pain: A systematic review and meta-analysis

BACKGROUND

Arterial puncture-related pain remains unaddressed across several clinical settings. Analgesic techniques are not routinely employed before arterial puncture despite the recommendation that local anesthesia be used, except in emergencies. A comprehensive review of interventions aimed at reducing arterial puncture-related pain and their potential effectiveness is lacking, and the benefit of some interventions is uncertain.

OBJECTIVE

To describe interventions aimed at reducing arterial puncture-related pain and provide an estimate of their effectiveness.

DESIGN

Systematic review and meta-analysis (PROSPERO no. CRD42020212299).

DATA SOURCE(S)

PubMed, CINAHL EBSCO, EMBASE, the Cochrane Database of Systematic Reviews, and Scopus were searched from their inception to 7 October 2020. No temporal or language limits were applied.

METHODS

Published, quantitative studies on interventions aimed at reducing arterial puncture-related pain among adults were included. Screening, quality appraisal, and data extraction were undertaken independently by two reviewers. Random effects meta-analyses were performed to assess the association between interventions aimed at reducing arterial puncture-related pain and patients' perceived pain using difference in means (MD) with 95% confidence intervals (CIs). A funnel plot and Egger test were used to assess publication bias.

RESULTS

The titles and abstracts of the 2446 identified articles were screened, and 43 and 31 studies were finally included in the systematic review and meta-analysis, respectively. Interventions to reduce arterial puncture-related pain included: topical anesthetics (n = 16), cryotherapy (n = 9), local anesthetic infiltration (n = 5), narrower needle gage (n = 5), ultrasound-guided procedure (n = 3), topical anesthetics combined with local anesthetic infiltration (n = 1), iontophoresis using anesthetics (n = 1), engineered blood gas syringe (n = 1), jet injector (n = 1), and local massage (n = 1). Topical anesthetics [MD -0.58, 95% CI -1.00, -0.15], cryotherapy [MD -1.13, 95% CI -1.72, -0.53], and local anesthetic infiltration [MD -1.13, 95% CI -1.72, -0.53] reduced arterial puncture-related pain. No benefit was found for narrower needle gage [MD -0.07, 95% CI -0.86, 0.71] or ultrasound-guided procedure [MD -1.74, 95% CI -3.51, 0.03]. No publication bias was detected.

CONCLUSIONS

Local anesthetic infiltration provided the greatest pain reduction and should be considered standard practice. Cryotherapy may be a safe, convenient alternative to local anesthetic infiltration. Topical anesthetics had limited benefit, and their lengthy time of onset makes them unsuitable for critical or emergency situations, though they may represent an option when comorbid conditions make cooling impossible. Caution must be used when interpreting these results, given the high risk of bias in the methods of included studies and the heterogeneity across the studies.

Mathematically arterialised venous blood is a stable representation of patient acid-base status at steady state following acute transient changes in ventilation

Hyper- or hypoventilation are commonly occurring stress responses to arterial puncture around the time of blood sampling and have been shown to rapidly alter arterial blood acid–base parameters. This study aimed to evaluate a physiology-based mathematical method to transform peripheral venous blood acid–base values into mathematically arterialised equivalents following acute, transient changes in ventilation. Data from thirty patients scheduled for elective surgery were analysed using the physiology-based method. These data described ventilator changes simulating ‘hyper-’ or ‘hypoventilation’ at arterial puncture and included acid–base status from simultaneously drawn blood samples from arterial and peripheral venous catheters at baseline and following ventilatory change. Venous blood was used to calculate mathematically arterialised equivalents using the physiology-based method; baseline values were analysed using Bland–Altman plots. When compared to baseline, measured arterial and calculated arterialised values at each time point within limits of pH: ± 0.03 and PCO₂: ± 0.5 kPa, were considered ‘not different from baseline’. Percentage of values considered not different from baseline were calculated at each sampling timepoint following hyper- and hypoventilation. For the physiological method, bias and limits of agreement for pH and PCO₂ were -0.001 (-0.022 to 0.020) and -0.02 (-0.37 to 0.33) kPa at baseline, respectively. 60 s following a change in ventilation, 100% of the mathematically arterialised values of pH and PCO₂ were not different from baseline, compared to less than 40% of the measured arterial values at the same timepoint. In clinical situations where transient breath-holding or hyperventilation may compromise the accuracy of arterial blood samples, arterialised venous blood is a stable representative of steady state arterial blood.

Effect of Local Anesthesia on Pain During Arterial Puncture: The GAEL Randomized Placebo-Controlled Trial

BACKGROUND

Arterial puncture is often painful for patients. The aim of this study was to compare use of local anesthesia as a eutectic mixture of 2 local anesthetics, lidocaine and prilocaine, versus placebo.

METHODS

We conducted a double-blind, randomized controlled trial. Subjects were eligible if arterial puncture was indicated. The primary outcome was an experienced pain > 2 on a numerical pain rating scale. As having had a previous experience of arterial puncture was expected to be predictive of the current response, we planned 3 comparisons between use of local anesthesia and placebo: in the whole sample, among subjects with a painful previous experience, and among subjects with a painless previous experience. Multiple testing was analyzed using the Bonferroni correction for the primary outcome. The secondary outcome was the numerical pain rating scale score itself. All analyses were performed on an intention-to-treat basis.

RESULTS

A total of 136 subjects were included in this study. The primary outcome occurred in 20.9% in the active arm versus 37.7% in the placebo arm in the whole sample (relative risk 0.55; 95% CI when adjusting for multiple testing ranged was 0.28-1.09, P = .10; 95% CI without adjustment was 0.32-0.97, P = .038). No significant heterogeneity in the study treatment effect was found when considering previous painful or painless arterial puncture (P = .70). The numerical pain rating scale score was 1.55 ± 2.03 in active group versus 2.09 ± 2.15 in the placebo group (P = .13).

CONCLUSIONS

We found that application of a eutectic mixture reduced the number of painful arterial punctures by 50% compared with placebo. However, this result was not statistically significant. (ClinicalTrials.gov registration NCT01964248.).

Is venous blood a more reliable description of acid-base state following simulated hypo- and hyperventilation?

Background

ABGs are performed in acute conditions as the reference method for assessing the acid-base status of blood. Hyperventilation and breath-holding are common ventilatory changes that occur around the time of sampling, rapidly altering the ‘true’ status of the blood. This is particularly relevant in emergency medicine patients without permanent arterial catheters, where the pain and anxiety of arterial punctures can cause ventilatory changes. This study aimed to determine whether peripheral venous values could be a more reliable measure of blood gases following acute changes in ventilation.

Methods

To allow for characterisation of ventilatory changes typical of acutely ill patients, but without the confounding influence of perfusion or metabolic disturbances, 30 patients scheduled for elective surgery were studied in a prospective observational study. Following anaesthesia, and before the start of the surgery, ventilator settings were altered to achieve a + 100% or − 60% change in alveolar ventilation (‘hyper-’ or ‘hypoventilation’), changes consistent with the anticipation of a painful arterial puncture commonly encountered in the emergency room. Blood samples were drawn simultaneously from indwelling arterial and peripheral venous catheters at baseline, and at 15, 30, 45, 60, 90 and 120 s following the ventilatory change. Comparisons between the timed arterial (or venous) samples were done using repeated-measures ANOVA, with post-hoc analysis using Bonferroni’s correction.

Results

Arterial blood pH and PCO₂ changed rapidly within the first 15–30s after both hyper- and hypoventilation, plateauing at around 60s (∆pH = ±0.036 and ∆PCO₂ = ±0.64 kPa (4.7 mmHg), respectively), with peripheral venous values remaining relatively constant until 60s, and changing minimally thereafter. Mean arterial changes were significantly different at 30s (P < 0.001) when compared to baseline, in response to both hyper- and hypoventilation.

Conclusion

This study has shown that substantial differences in arterial and peripheral venous acid-base status can be due to acute changes in ventilation, commonly seen in the ER over the 30s necessary to sample arterial blood. If changes are transient, peripheral venous blood may provide a more reliable description of acid-base status.

Reducing pain by using venous blood gas instead of arterial blood gas (VEINART): a multicentre randomised controlled trial

Introduction

Venous sampling for blood gas analysis has been suggested as an alternative to arterial sampling in order to reduce pain. The main objective was to compare pain induced by venous and arterial sampling and to assess whether the type of sampling would affect clinical management or not.

Methods

We performed an open-label randomised multicentre prospective study in four French EDs during a 4-week period. Non-hypoxaemic adults, whose medical management required blood gas analysis, were randomly allocated using a computer-generated randomisation list stratified by centres with an allocation ratio of 1:1 using random blocks to one of the two arms: venous or arterial sampling. The primary outcome was the maximal pain during sampling, using the visual analogue scale. Secondary outcomes pertained to ease of sampling as rated by the nurse drawing the blood, and physician satisfaction regarding usefulness of biochemical data.

Results

113 patients were included: 55 in the arterial and 58 in the venous sampling group. The mean maximal pain was 40.5 mm±24.9 mm and 22.6 mm±20.2 mm in the arterial group and the venous group, respectively, accounting for a mean difference of 17.9 mm (95% CI 9.6 to 26.3) (p<0.0001). Ease of blood sampling was greater in the venous group as compared with the arterial group (p=0.02). The usefulness of the results, evaluated by the prescriber, did not significantly differ (p=0.25).

Conclusions

Venous blood gas is less painful for patients than ABG in non-hypoxaemic patients. Venous blood gas should replace ABG in this setting.

Trial registration number

NCT03784664.

Evaluation of an improved small gauge needle for venipuncture in children with difficult venous access: Impact on sample quality, phlebotomist satisfaction and patient pain perception

BACKGROUND

Smaller needles gauge (G) may reduce pain and improve vein access in difficult venous access (DVA). Aims were to compare the performances of two Beckton-Dickinson (BD) Vacutainer® Blood Collection Sets in a pediatric setting: UltraTouch™ Push Button (UT-PBBCS) and Safety-Lok™ (SLBCS).

MATERIALS AND METHODS

Questionnaires were used to record venipuncture features, patient pain perception and phlebotomist difficulty score. Specimen quality was evaluated by hemolysis index (HI) on Roche Cobas® 6000.

RESULTS

SLBCS (21/23G) or UT-PBBCS (23/25G) were used in 211 (50.2%) and 209 (49.8%) subjects. Pain was associated with age (p < 0.0001) and was lower in UT-PBBCS (p = 0.0339). Difficulty was significantly associated with age (p = 0.002), not with needle gauge (p = 0.461) and it was 0.42 points lower in UT-PBBCS. HI was not associated with blood collection set (p = 0.385).

CONCLUSIONS

UT-PBBCS globally performed better than SLBCS and could enhance phlebotomy and patient comfort, without affecting sample quality in pediatric patients with DVA.

Arterial blood gas sampling: using a safety and pre-heparinised syringe

Taking arterial blood gases (ABG) is an essential part of the diagnosis and management of critically ill patients. An arterial blood sample is collected from an artery, primarily to determine the ABGs. Health professionals should only undertake this if the procedure is in the legal scope of practice for their profession in their country, and they have demonstrated skilled, proficient, safe practice after formal training. Blood samples can be obtained via an arterial catheter inserted into an artery or percutaneously by using a needle to directly puncture into the artery. This article provides an overview of this subject area. It includes case studies where the Pulsator Plus Arterial Blood Gas Syringe (Smiths Medical) was used to safely and effectively collect blood samples for analysis.

Ultrasound guidance in difficult radial artery puncture for blood gas analysis: A prospective, randomized controlled trial

Background

Ultrasound (US) guidance has yet to prove its applicability in radial arterial blood gas analysis (ABGA) punctures. The main objective of our study was to compare the number of first-attempt successes (NFAS) for radial arterial puncture in difficult patients with or without US guidance. The Secondary aims were to compare the number of punctures (NOP), puncture time, and patient pain.

Methods

In this single-center, randomized controlled trial, patients who required a radial ABGA and in whom the arterial puncture was assessed as difficult (because of non-palpable radial arteries or two previous puncture failures by a nurse) were assigned to the US group or no-US (NUS) group (procedure performed by a trained physician).

Results

Thirty-six patients were included in the US group and 37 in the NUS groups. The NFAS was 7 (19%) in the NUS group and 19 (53%) in the US group. The relative risk of success in the US group was 2.79 (95% CI,1.34 to 5.82), p = 0.01. In the NUS and US groups, respectively, the median NOP was 3 [2; 6] vs. 1 [1; 2], estimated difference −2.0 (95%CI, −3.4 to −0.6), p < 0.01; the respective puncture time was 3.1 [1.6; 5.4] vs. 1.4 [0.6; 3.1] min, estimated difference −1.45 (95%CI, −2.57 to −0.39), p = 0.01; the respective median patient pain was 6 [4; 8] vs. 2 [1; 4], estimated difference −4.0 (95%CI, −5.8 to −2.3); p < 0.01.

Conclusion

US guidance by a trained physician significantly improves the rate of success in difficult radial ABGA patients.

Risk of malignancy in thyroid nodules: predictive value of puncture feeling of grittiness in the process of fine-needle aspiration

Fine-needle aspiration cytology (FNAC) is widely used for diagnosing thyroid nodules. However, there has been no specific investigation about the puncture feeling of grittiness. The aim of the present study was to see if the puncture feeling of grittiness during fine-needle aspiration procedure, combined with standard FNAC, could improve the accuracy in diagnosing thyroid cancer. A total of one thousand five hundred and thirty-one thyroid FNAC specimens acquired between January 2013 and January 2017 were retrospectively retrieved. All cases underwent surgical intervention. The FNAC diagnoses and puncture feeling of grittiness were evaluated and compared with the results of final histopathological diagnoses. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of diagnosis for thyroid nodules by FNAC alone, puncture feeling of grittiness alone, and the combination of FNAC plus grittiness were calculated respectively. The findings of our study suggest that puncture feeling of grittiness is a useful adjunct. Adding puncture feeling of grittiness to FNAC can significantly enhance the ability to differentiate malignant thyroid nodules from benign thyroid nodules. More importantly, we found that puncture feeling of grittiness is surprising trust-worthy in being near perfectly reproducible per individual radiologist, and among different operators.

Evaluation of Pain and Specimen Quality by Use of a Novel 25-Gauge Blood Collection Set With Ultra-Thin Wall Cannula and 5-Bevel Tip Design

BACKGROUND

Phlebotomy has significant impact on overall patient satisfaction. Smaller gauge needles, such as a 25 gauge, may lessen patient discomfort but increase hemolysis and tube-filling times. Our studies evaluated the effect of a 5-bevel, 25-gauge blood collection set (BCS) with ultra-thin wall cannula [BD Vacutainer® UltraTouch™ Push Button BCS (UltraTouch)] on patient pain and anxiety compared with two 3-bevel, thin-wall, 23-gauge BCSs [BD Vacutainer® Safety-Lok™ (Safety-Lok) and Greiner Bio-One Vacuette® (Vacuette)]. Our studies also evaluated the 25-gauge UltraTouch for sample quality and tube filling compared with the 3-bevel, thin-wall, 23-gauge BD Vacutainer Push Button BCS.

METHODS

We conducted 2 studies with 214 subjects to compare pain and anxiety regarding future phlebotomy with the 3 aforementioned devices. Another study with 52 subjects assessed hemolysis in specimens collected with the UltraTouch and Push Button BCS; bench testing evaluated tube-filling times with these devices. A questionnaire captured pain upon needle insertion, overall pain, and anxiety regarding future phlebotomy. Hemolysis was evaluated visually, by Hemolysis Index and hemolysis-sensitive indicators potassium (K) and lactate dehydrogenase (LDH).

RESULTS

A statistically significant decrease was noted for overall pain with UltraTouch compared with Vacuette and with insertion pain compared with Safety-Lok. There was no significant difference in anxiety regarding future phlebotomy. No increase was observed in Hemolysis Index, K or LDH. Tube-filling times were comparable for each device.

CONCLUSIONS

The 25-gauge UltraTouch provided less overall pain compared with the 23-gauge Vacuette, less pain upon needle insertion than the 23-gauge Safety-Lok, and no compromise in specimen quality or flow rate.

Research Lumbar Punctures among African Americans and Caucasians: Perception Predicts Experience

African Americans are under-represented in Alzheimer's disease (AD)-related biomarker studies, and it has been speculated that mistrust plays a major factor in the recruitment of African Americans for studies involving invasive procedures such as the lumbar puncture (LP). We set out to determine factors associated with non-participation in a biomarker study aiming to explore cerebrospinal fluid (CSF) AD biomarker differences between older African Americans and Caucasians. We also surveyed participants' procedure-related perception (a standard medical procedure vs. a frightening invasive procedure) and reluctance, as well as the rate and type of post-procedure discomfort and complications. Among 288 subjects approached for study participation, 145 (50.3%) refused participation with concerns over LP being the most commonly reported reason. Relatively more African Americans than Caucasians reported concerns over LP as the main reason for non-participation (46% vs. 25%, p = 0.03), but more African Americans also did not provide a specific reason for non-participation. Among those who completed study participation (including the LP), African Americans and Caucasians were similar in pre-LP perceptions and reluctance, as well as post-LP rates of discomfort or complication. Perceiving LP as a frightening invasive procedure, not race, is associated with increased likelihood of post-LP discomfort or complication (RR 6.2, 95% confidence interval 1.1-37.0). Our results indicate that LP is a well perceived procedure in a cohort of African American and Caucasian research participants, and is associated with few serious complications. The pre-procedure perception that the LP is a frightening invasive procedure significantly increases the risk of self-reported discomfort of complications, and African Americans may be more likely to turn down study participation because of the LP. Future studies will need to address factors associated with negative LP perceptions to further assure participants and reduce complication rates.

Agreement between arterial and venous lactate in emergency department patients: a prospective study of 157 consecutive patients

INTRODUCTION

In the emergency department (ED), lactate is routinely used for risk stratification. Whether venous or arterial lactate measured on blood gas is interchangeable is not known. We hypothesized that venous lactate can be used instead of arterial lactate for the evaluation of acute patients in the ED.

PATIENTS AND METHODS

This was a prospective single-center study. All patients requiring a lactate measurement were enrolled and we simultaneously drew arterial and venous blood. We followed up all patients to hospital discharge. Our primary aim was to evaluate agreements between the two measurements using Bland and Altman plots with the report of bias (mean difference) and limits of agreements. We also aimed to determine the rate of misclassification (defined as one measurement<1.8 mmol/l and the other>2.2). Our secondary aim was to evaluate their respective prognostic value to predict in-hospital death or admission in the ICU longer than 72 h.

RESULTS

The mean age of the 132 analyzed patients was 62 years (SD: 18 years), and 59% were men. The mean difference (bias) between arterial and venous lactate was -0.6 mmol/l (limits of agreement: -1.7 to 0.6 mmol/l). The rate of misclassification was 8% (95% confidence interval: 3-2%). Both methods present similar performances for the prediction of poor outcomes, with an area under the receiving operator characteristic curves of 0.67 for both. Results were similar when focused only on septic patients.

CONCLUSION

Venous and arterial lactates do not agree well, and there is a high misclassification rate. Venous lactate does not appear to be interchangeable with arterial sampling.